Heat 1/4 cup of the olive oil in a large pot over medium heat and cook the tomatoes for 5 minutes. Season with salt and pepper and pour in 6 cups of the water or broth. Bring to a boil and add more salt if necessary. Add the pasta to the boiling soup and cook until tender. Add more of the water or broth if the soup is too thick. Pour in the remaining olive oil at the end. Serve warm, topped with the crumbled feta.